Note: The release image is a composite of the F814W (I) data from proposal 11710, taken May 29 - July 8, 2010, and F475W (g), F625W (r), F775W (i), and F850LP (z) data from proposal 9289, PI: H. Ford (JHU), taken June 12 - 21, 2002.

This image is a composite of separate exposures acquired by the ACS instrument on the Hubble Space Telescope (HST). Several filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are:

Peering deep into the heart of the massive galaxy cluster Abell 1689, NASA's Hubble Space Telescope has nabbed more than 160,000 globular clusters, the largest population ever seen.

The image at left, taken by Hubble's Advanced Camera for Surveys, shows the numerous galaxies that make up Abell 1689. The box near the center outlines one of the regions sampled by Hubble, containing a rich collection of globular clusters.

The monochromatic view at right, taken at visible wavelengths, zooms into the region packed with globular clusters. They appear as thousands of tiny white dots, which look like a blizzard of snowflakes. The larger white blobs are entire galaxies of stars.

Globular clusters, dense collections of hundreds of thousands of stars, are the homesteaders of galaxies, containing some of the oldest surviving stars in the universe. Almost 95 percent of globular cluster formation occurred within the first 1 billion or 2 billion years after our universe was born in the big bang 13.7 billion years ago.

Hubble's Advanced Camera for Surveys snapped these images from June 12 to 21, 2002, and between May 29 and July 8, 2010.

Members of the science team are John Blakeslee; Karla Alamo-Martinez and Rosa Gonzalez-Lopezlira, Center for Radio Astronomy and Astrophysics of the National Autonomous University of Mexico, in Morelia; Myungkook James Jee, University of California, Davis; Patrick Cote and Laura Ferrarese, DAO/NRC Herzberg Astrophysics; Andres Jordan, Pontifical Catholic University of Chile, in Santiago; Gerhardt Meurer, International Centre of Radio Astronomy Research, University of Western Australia, in Perth; Eric Peng, Kavli Institute for Astronomy and Astrophysics, Peking University; and Michael West, Maria Mitchell Observatory, in Nantucket, Mass.